# Author:sp
# CreaTime: $(DATE)
# FileName: $(NAME)
# Description: simple introdution of the code

'''字典是一个动态结构，可以随时在其中添加键值对'''
scores={'jack':100,'tom':59,'marry':80}
'''key值的判断'''
print('jack' not in scores)
print('ni' in scores)
'''字典元素的删除'''
del scores['jack']
#scores.clear()         清空字典元素
#删除的键值对会永远消失
print(scores)
'''增加字典元素'''
scores['jack']=99
print(scores)
scores['jack']=77     #修改字典元素的值
print(scores)